Evaluating MAX 7000S Device Utilization & Fitting
T E C H N I C A L B R I E F 3 3 D E C E M B E R 1 9 9 7
M-TB-033-01
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Introduction
MAX® 7000S devices are based on Altera’s second-generation MAX architecture and provide 600 to 5,000 usable gates, 32 to 356 macrocells, pin-to-pin delays as fast as 5 ns, and counter speeds of up to 178.6 MHz.
The devices also support advanced features such as in-system programmability (ISP), built-in JTAG support (for devices with 128 or more macrocells), and MultiVolt™ I/O operation (except in 44-pin devices).
Combined with support from the Altera® MAX+PLUS® II development system, MAX 7000S devices also offer efficient device utilization and superior fitting, enhancing overall performance. This technical brief evaluates device utilization and first- and second-time fitting by comparing MAX 7000S performance to Xilinx XC9500 devices.
Device Utilization
Altera Applications recently conducted device-utilization experiments of both Altera EPM7128S devices and Xilinx XC95108 devices. Of 37 designs used in the experiments, XC9500 devices used an average of 7% more macrocells than MAX 7000S devices. Table 1 shows the average number of macrocells required by EPM7128S and XC95108 devices. As the utilization rate of the XC95108 device increased, its macrocell efficiency decreased. The XC95108 devices used 90% to 100% of available macrocells.
Table 1. Average Number of Macrocells Used Note (1)
Note:
(1) The EPM7128S device results were generated using the default setting in the Altera MAX+PLUS II software, version 8.1; the XC95108 device results were generated using the default setting in the Xilinx XACT software, version 6.01.
Device Fitting & Performance
Altera Applications also performed a benchmark study of 40 designs to test first- and second-time fitting rates of MAX 7000S and XC9500 devices. Table 2 shows the percentages of successful first- and second- time fitting for EPM7128S and XC95108 devices at 90% macrocell utilization.
Table 2. First- & Second-Timing Fitting with 90% Macrocell Utilization Note (1)
Note:
(1) The EPM7128S device results were generated using the default setting in the Altera MAX+PLUS II software, version 8.1; the XC95108 device results were generated using the default setting in the Xilinx XACT software, version 6.01.
Device Macrocells Used
EPM7128S 96
XC95108 103
Device First-Time Fitting Second-Time Fitting
EPM7128S 100% 60%
XC95108 50% 43%
Copyright 1997 Altera Corporation. Altera, MultiVolt, MAX, MAX+PLUS, MAX+PLUS II, MAX 7000, MAX 7000S, and EPM7128S are trademarks and/or service marks of Altera Corporation in the United States and/or other countries. Other brands or products are trademarks of their respective holders. All rights reserved.
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The results show that MAX 7000S devices have a more successful first- and second-timing fitting rate than XC9500 devices. When the XC95108 device’s macrocells were 90% utilized, the first-and second-time fitting rates were 50% and 43%, respectively. In contrast, when the EPM7128S device’s macrocells were 90% utilized, the first- and second-time fitting rates were 100% and 60%, respectively.
The benchmark study also showed that MAX 7000S devices out-performed XC9500 devices by 10%.
Moreover, the EPM7128S devices maintained this 10% performance advantage through second-time fitting. Table 3 shows each devices’ performance rate for first- and second-time fitting. In this example, -7 speed grade EPM7128S and XC95108 devices were used.
Table 3. First- & Second-Timing Fitting Performance Rates Note (1)
Note:
(1) The EPM7128S device results were generated using the default setting in the Altera MAX+PLUS II software, version 8.1; the XC95108 device results were generated using the default setting in the Xilinx XACT software, version 6.01.
The Altera Applications experiments showed that MAX 7000S devices used macrocells more efficiently than XC9500 devices, especially when utilization rates were high. The experiments also showed that MAX 7000S devices have a higher percentage of successful first-and second-time fittings and can out- perform XC9500 devices by maintaining a 10% performance advantage through second-time fitting.
The documents listed below provide more detailed information. Part numbers are in parentheses.
■ In-System Programmability Handbook (M-HB-ISP-01)
■ MAX 7000 Programmable Logic Device Family Data Sheet (A-DS-M7000-04)
You can request documents from:
■ Altera Literature Services at (888) 3-ALTERA
■ World-wide web at http://www.altera.com
■ Your local Altera sales representative
Device Performance (fMAX)
First-Time Fitting (MHz) Second-Time Fitting (MHz)
EPM7128S 87.9 79.8
XC95108 77.3 72.2
